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Hans Ivar Riesel's 90th Birthday Challenge starts May 24th 2019 00:00 UTC

PrimeGrid - Št, 23.05.2019 - 11:29
To celebrate Hans Ivar Riesel's birthday, PrimeGrid is having a 7 day challenge from May 24th 2019, 00:00 UTC until May 31st, 00:00 UTC. Work units from the TRP (LLR) project, which are downloaded and completed during the challenge will count towards your challenge score. Help us celebrate, maybe find a really big prime number eliminating one of the Riesel k's for Riesel's birthday and earn a cool new badge! Best estimate is 30% chance someone finds a prime during the challenge. For more information and discussion, please see the official challenge thread:
Kategórie: Novinky z projektov

AVX-512 Now Supported by LLR

PrimeGrid - St, 22.05.2019 - 02:22
All of PrimeGrid's LLR applications now support AVX-512 on CPUs with that capability. Those of you that have been using app_info.xml/anonymous platform to run LLR 3.8.23 may now use the stock app if you wish, which is also LLR 3.8.23. UPDATE May 22nd: It has come to my attention that while CPUs with 2 AVX-512 execution units gain a substantial boost in performance, mid-range CPUs with only 1 AVX-512 execution unit may see a significant decrease in performance with the new LLR app. Obviously, this is not intended. For the time being there is no workaround for this. If you have a CPU that supports AVX-512, but has only a single AVX-512 execution unit, you may want to use the anonymous platform mechanism (app_info.xml) to run the older version of LLR. With a challenge starting tomorrow, we won't make changes to the app until at least a week. We apologize for any inconvenience this may cause. UPDATE May 23rd: I've included a list of single and dual unit AVX-512 CPUs here.
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20 years and counting!

SETI@Home - Pi, 17.05.2019 - 19:39
Happy Anniversary! On this date in 1999, SETI@home came online. Since then millions of our volunteers have helped us sift through petabytes of data from multiple radio telescopes. ET still hasn't shown up to the party.

We're not discouraged. We're able to examine less than a tenth of a percent of the radio spectrum, over only 1/3 of the sky and a limited number of additional stars. But our capabilities are increasing every day. In 1999 it took up to a week to process a single workunit on a home PC. Now, on a machine with a GPU, it might only take a few minutes to do a far more detailed and more sensitive analysis. Who knows what the next 20 years will bring?
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New acemd

GPUGRID - Št, 16.05.2019 - 17:49
HI, we are testing a new application that will provide Turing support based on the new application acemd v3. For now we have deprecated the linux version of v2 and we will soon release v3 for linux using a boinc wrapper. If the boinc wrapper works, then it should be easy because the application works by itself and it has been tested extensively. gdf
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SETI Perspectives article "Coming of Age for Optical SETI"

SETI@Home - Pi, 10.05.2019 - 20:52
Richard Lawn has written a new article, this one on the Panoramic Optical SETI effort, PANOSETI. As a bonus he includes a bit of an update on 'Oumuamua.
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Thanks for supporting SixTrack at LHC@Home and updates

LHC@home - Ut, 23.01.2018 - 19:08
Dear volunteers,

All members of the SixTrack team would like to thank each of you for supporting our project at LHC@Home. The last weeks saw a significant increase in work load, and your constant help did not pause even during the Christmas holidays, which is something that we really appreciate!

As you know, we are interested in simulating the dynamics of the beam in ultra-relativistic storage rings, like the LHC. As in other fields of physics, the dynamics is complex, and it can be decomposed into a linear and a non-linear part. The former allows the expected performance of the machine to be at reach, whereas the latter might dramatically affect the stability of the circulating beam. While the former can be analysed with the computing power of a laptop, the latter requires BOINC, and hence you! In fact, we perform very large scans of parameter spaces to see how non-linearities affect the motion of beam particles in different regions of the beam phase space and for different values of key machine parameters. Our main observable is the dynamic aperture (DA), i.e. the boundary between stable, i.e. bounded, and unstable, i.e., unbounded, motion of particles.

The studies mainly target the LHC and its upgrade in luminosity, the so-called HL-LHC. Thanks to this new accelerator, by ~2035, the LHC will be able to deliver to experiments x10 more data than what is foreseen in the first 10/15y of operation of LHC in a comparable time. We are in full swing in designing the upgraded machine, and the present operation of the LHC is a unique occasion to benchmark our models and simulation results. The deep knowledge of the DA of the LHC is essential to properly tune the working point of the HL-LHC.

If you have crunched simulations named "workspace1_hl13_collision_scan_*" (Frederik), then you have helped us in mapping the effects of unavoidable magnetic errors expected from the new hardware of the HL-LHC on dynamic aperture, and identify the best working point of the machine and correction strategies. Tasks named like "w2_hllhc10_sqz700_Qinj_chr20_w2*" (Yuri) focus the attention onto the magnets responsible for squeezing the beams before colliding them; due to their prominent role, these magnets, very few in number, have such a big impact on the non-linear dynamics that the knobs controlling the linear part of the machine can offer relevant remedial strategies.

Many recent tasks are aimed at relating the beam lifetime to the dynamic aperture. The beam lifetime is a measured quantity that tells us how long the beams are going to stay in the machine, based on the current rate of losses. A theoretical model relating beam lifetime and dynamic aperture was developed; a large simulation campaign has started, to benchmark the model against plenty of measurements taken with the LHC in the past three years. One set of studies, named "w16_ats2017_b2_qp_0_ats2017_b2_QP_0_IOCT_0" (Pascal), considers as main source of non-linearities the unavoidable multipolar errors of the magnets, whereas tasks named as "LHC_2015*" (Javier) take into account the parasitic encounters nearby the collision points, i.e. the so called "long-range beam-beam effects".

One of our users (Ewen) is carrying out two studies thanks to your help. In 2017 DA was directly measured for the first time in the LHC at top energy, and nonlinear magnets on either side of ATLAS and CMS experiments were used to vary the DA. He wants to see how well the simulated DA compares to these measurements. The second study seeks to look systematically at how the time dependence of DA in simulation depends on the strength of linear transverse coupling, and the way it is generated in the machine. In fact, some previous simulations and measurements at injection energy have indicated that linear coupling between the horizontal and vertical planes can have a large impact on how the dynamic aperture evolves over time.

In all this, your help is fundamental, since you let us carry out the simulations and studies we are interested in, running the tasks we submit to BOINC. Hence, the warmest "thank you" to you all!
Happy crunching to everyone, and stay tuned!

Alessio and Massimo, for the LHC SixTrack team.
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LHC@home down-time due to system updates

LHC@home - Ut, 23.01.2018 - 11:19
Tomorrow Wednesday 24/1, the LHC@home servers will be unavailable for a short period while our storage backend is taken down for a system update.

Today, Tuesday 23/1, some of the Condor servers that handle CMS, LHCb and Theory tasks will be down for a while. Regarding the on-going issues with upload of files, please refer to this thread.

Thanks for your understanding and happy crunching!
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